Baine Quinlyn, Hughes Daniel W W, Casares Emily E, Martinson Ellen O, Martinson Vincent G
Department of Biology, University of New Mexico, Albuquerque, NM 87131, USA.
Proc Biol Sci. 2024 Dec;291(2036):20242424. doi: 10.1098/rspb.2024.2424. Epub 2024 Dec 11.
The evolution of diverse and novel morphological traits is poorly understood, especially how symbiotic interactions can drive these adaptations. The extreme diversity of external traits in insect-induced galls is currently explained by the Enemy Hypothesis, in which these traits have selective advantage in deterring parasitism. While previous tests of this hypothesis used only taxonomic identity, we argue that ecologically functional traits of enemies (i.e. mode of parasitism, larval development strategy) are a crucial addition. Here, we characterize parasitoid guild composition across four disparate gall systems and find consistent patterns of association between enemy guild and gall morphology. Specifically, galls with a longer average larva-to-surface distance host a significantly higher proportion of enemies with a distinct combination of functional traits (i.e. ectoparasitic, idiobiont, elongate ovipositor). Our results support the Enemy Hypothesis and highlight the importance of species ecology in examining insect communities and the evolution of novel defensive characters.
人们对多样且新颖的形态特征的演化了解甚少，尤其是共生相互作用如何推动这些适应性变化。目前，昆虫虫瘿外部特征的极端多样性是由“敌人假说”来解释的，该假说认为这些特征在阻止寄生方面具有选择优势。虽然此前对这一假说的检验仅使用了分类学特征，但我们认为敌人的生态功能特征（即寄生方式、幼虫发育策略）是一个至关重要的补充。在此，我们描述了四个不同虫瘿系统中的寄生蜂群落组成，并发现敌人群落与虫瘿形态之间存在一致的关联模式。具体而言，平均幼虫到表面距离较长的虫瘿，其具有特定功能特征组合（即体外寄生、独栖性、产卵器细长）的敌人比例显著更高。我们的结果支持了“敌人假说”，并强调了物种生态学在研究昆虫群落和新防御特征演化中的重要性。
